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(No Model.) 2 Sheets-Sheet 1.

L. S. GRAVES. SCREW ELEVATOR.

No. 309,538 Patented Dec. 23, 1884.

(N M del) '2 Sheet's-Sheet 2. 0 o i I L. S. GRAVES.

SCREW ELEVATOR.

No. 309,538. Patented Dec. 23, 1884.

N. PETERS. PllnloLAhagmphzr. Washmmnn. D, c.

lUivirien States PAT T @l l l'tllil.

LORENZO 8.. GRAVES, OF ROCHESTER, NEW YORK, ASSIGNOR S. GRAVES 8s SON, OF SAME lIL-AOE,

TO LORENZO SCREW-ELEVATOR.

PEDIPICATIQN forming part of Letters Patent No. 309,538, dated December 23, 1884.

Application tiled April 5, 1854. (No model.)

T0 at whom it nu/y concern.-

Be it known that I, LORENZO S. Gaavns, of Rochester, in the county of Monroe and State of New York, have invented certain Improvements in Elevators, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to certain improvements in elevators of that class in which mo tion is communicated to the windingd rum by means of a revolving screw and and which. improvements are fully described in the following specification, the novel features thereof being specified in the claims hereunto annexed.

My improvements in elevators are represented in the accompanying drawings, in which Figure l is a side view of an elevator in the position occupied by it when in use, at tached to the ceiling or other suitable sup port. Fig. 2 represents the same as seen from below. Figs. 3 and at show the mode of attaching the brake-shoe to the biakelever. Fig. 5 is a section on the line 1 ;1 Figs. 1. and 2. Figs. 6 and 7 are views of the cam on the shifter-shaft, as seen from the inside. Fig. 8 is a section of the cam on the line r Fig. 6. Fig. 9 is a side view of the traveling nut on the shifter-shaft. Fig. 10 shows the automatic stop-motion on the shifter-shaft. Fig. 11 is a side view of the cam and roller which operate the brake.

In the accompanying drawings, A. A are the side frames of my improved elevator; B, the cabledrum; G, the screw; D, the screw gear; E, the cam for shifting the belts from the loose pulleys K and N onto the tight pulley L; F, the wheel for the starting-rope; H, the brake-wheel, and O the hanger at the outer end of the screw-shaft (Z. The side frames, A A, are made of suitable size and shape to support the winding drum B, which revolves therein in suitable bearings, f f, at each end of the drum. The drum is preferably cast in one piece, having on each end the journals 0 c, fitted within the bearings f f, and its outer surface being provided with a spiral groove or grooves for the reception of the cable or cables. The worm-gear D consists of a suitable toothed ring, secured to the drum inside of one of or bolts.

the journals f'by means of screws The screw 0 is arranged to mesh with the teeth of the worn'r gear, being placed on the shaft (Z at right angles with the axis of the drum and above the screw-gear or between it and the ceiling or support to which the elevator is attached.

forged on The screw 0 is or otherwise secured to the worm shaft (1, which also carries the tight pulley L,

loose pulleys K and N,

and the brake-wheel The wornrshaft revolves in suitable bearings placed on the inner face of the frame A at each side of the screw, its outer end being supported the hanger O.

in a suitable bearing, it, carried by In the practical operation of the machine motion is imparted to the screw-shaft d by two belts traveling in opposite directions, which are shifted onto the ti gh elevator is at work, but

pulleys K use. rection or drum to rotate and to lifting-cable 11, Fig.

t pulley L when the which run on the loose and N when the machine is not in As the screw-shaft revolves in one di-' the other it causes the windingwind or unwind the 1, thereby raising or lowering an elevator-platform which is attached to the end of the eabl carryingwheel.

the cable screw-gear and screw, which is received by 20, at the end of the screw-shaft, supported by the hanger O.

tained by This end-thrust may be susa collar or collars 0n the shaft or by a screw, 3 Fig. 1, bearing against the end of the shaft.

from the loose back again, by

ends of .th

The belts are separately shifted pulleys to the tight pulley, or means of the shifters 217,011 the e sliding shifter-rods g and h, which are operated from the cam E by means of the 0 levers U and :r, rods are arranged to slide in guides, ZZ,

Figs. 1, 6, and The shiftersuitable ways or on the frame of the machine. The

lever '11 is pivoted on a stud at 6, attached to the frame,

block, 1", secured on the sliding so that as full and dotted lines its upper end being fitted into a shifter-rod g, the lever swings, asindicatcd by the in 1, the shifter is caused to slide in the guides Z Z and to shift the belt fr om the loose pulley N to the tight 10o pulley L. In a similar manner the lever 00 is arranged to transmit motion from the cam E to the shifter-rod h, being pivoted to the frame at f, Figs. 1 and 6, and connected to the rod by the block 8', Fig. 1. The shifter-rod h operates to shift the belt from the pulley K to the pulley L, or vice versa. At their lower ends the lever 11 and as are provided with the rollers n and k, which are fitted to the camgroove 0 in the inner face of the cam E. The cam E is secured to the shifter-shaft a, which passes centrally through the drum B, the journals e e of which are bored out to receive it. The shifter-shaft a. carries at one end the wheel or pulley F, to which the starting-rope is attached, by means of which apartial revolution is given to the cam E in either direction, thereby shifting the up or down belt onto or off the tight pulley L. The starting-rope is carried about suitable pulleys, if necessary, and passes up and down within the elevator well, being arranged so as to be conveniently under the control of a person riding on the elevator-platform, as is customary in this class of machines. The shifter-shaft or also carries the automatic stop-motion S T T, located within the cable-drum, by which the motion of the elevator is controlled when the platform reaches the top or bottom of the elevator-well.

The operation of the cam E will be readily understood by an inspection of Figs. 6 and 7 of the drawings. The cam is provided with a cam-groove, a portion of which, 0, extending half-way around the cam, is circular,wl1ile the other parts, 0 c, are curved inward toward the shifter-shaft for about one-fourth of a revolution, so that when the shifter-shaft is rotated in either direction for a quarter of a revolution, one of the levers is caused to swing on its pivot, thereby shifting the corresponding belt from the loose to the tight pulley, While the other lever is held at rest, and the belt which it controls will remain on the loose pulley over which it runs. Thus in Fig. 6 a quarter-turn j of the shifter-shaft and cam causes the end of the lever 00 to swing inward, as indicated in Fig. 7,thereby shifting the belt from the pulley K onto the tight pulley L, while the end of the lever 12 remains stationary, its roller a running in the circularpart c of the cam-groove.

I claim 1. The combination, with the revolving cable-drun1 of an elevator, of a shifter-shaft extending centrally through the drum, and provided with the automatic stop-motion located inside the drum, substantially as and for the purposes set forth.

2. The combination, with the revolving cable-drum of an elevator, provided with hollow journals 6 e, of the centrally-located shiftershaft 01, provided with the automatic stop-mo-- tion inside the drum, substantially as and for the purposes set forth.

3. The combination, wit-h the revolving cable-drum. B of an elevator, of the centrally-located threaded shifter-shaft a, traveling nut S, connected with the drum so as to revolve therewith, and stops T and T on each side the travcling nut, substantially as described.

4. The combination, with the revolving cable-drum of an elevator, of the automatic stop motion located within the drum, substantially as described.

5. The combination, with the revolving elevator-drum B, of the centrally-located threaded shiftershaft a, clamp-nuts T and T, and traveling nut S, connected to the interior of the drum so as to revolve therewith, ,substantially as described.

(5. The combination, with the revolving elevator-drum B, of the centrally-located shiftershaft to, provided with the automatic stop-mo tion within the drum, screw-gear D, screw and screw-shaft G d, brake-wheel H on the wormshaft, brake I, cam m, spring t, and connecting mechanism, as described, arranged to permit the spring to apply the brake under the control of the stop-motion, substantially as and for the purposes set forth.

7. The combination,with the drum B, ofthe screw -gear D, screw and screw-shaft G d, shifter- LORENZO S. GRAVES.

WVitnesses:

H. G. PHILLIPS, H. H. SOHLEBER. 

